Engine starter



Feb. 21, 1933. 'E AYTO 1,898,401

ENGINE STARTER Filed March 51, 1932 INVENTOR B Y gate/ 25 8 (swa m A TTORNEY Patented Feb. 21, 1933 UNITED STATES PATENT; orrlcs ROBERT E. SLAYTON, or ELMIRAQNEW YoRK, ASSIGNOR 'ro EcnIrsEMAcHINEcoM- IPANY, or ELMIR-A, NEW YoRK, A'coRroRA'rIoN or NEW YoRK r ENGINE srAR'rER Application filed March 31, 1932. Seria1;No. 602,299.

The present invention relates to starter gearing and more particularly to a rebound check for the pinion of a starter drive.

In starter drives of the type in which the pinion is automatically traversed into and out of engagement with an engine member, it is desirable to provide means for preventing the pinion from bounding back toward the engine gear when it is thrown out by the 1!? starting of the engine, since such rebounding may cause unnecessary noise and wear of the parts. 7

It is an object of the present invention to provide a novel and improved rebound check for starter pinions.

It is another object of the invention to provide such a device which is effective to dissipate the surplus energy of rotation of the pinion without interfering with the normal traversal of the pinion in the starting operation.

A further object is to provide such a device which is capable of exerting a powerful braking effect on the pinion without causing undue stresses or wear on the parts. 1 Another object is to provide such a device which is easily adapted to existing types of starting mechanism without appreciably altering the symmetry thereof.

Another object is to provide such a device which is simple and economical in construction and efficient and reliable in operation.

Further objects and advantages will be apparent to those skilled in this art from the following description taken in connection with the accompanying drawing in which:

Fig. 1 is a side elevation of a starter drive embodying a preferred form of the invention, the parts being shown in idle position; Fig. 2 is a section taken substantially on i the line 2-2 of Fig. 1;

Fig. 3 is a View similar to Fig. 2 showing he parts of the rebound check in operative position;

Fig. 4 is a view similar to Fig. 2 of a second embodiment of the invention; and

Fig. 5 is a view similar to Fig. 4 showing the parts in locking position.

Referring first to Fig. 1 of the drawing there is illustrated a power shaft 1 which may be the extended armature shaft of a starting motor, not shown. A hollow, shaft 2 is slidably-j ournalled onthe shaft 1 and is adapted to be driven therefrom by suitable means such as a spring 3 anchored as indicated at 4 and 5 to driving and driven heads 6 and 7 fixed respectively to the power shaft 1 and the hollow shaft 2 in any suitable manner.

The hollow shaft 2 is threaded for a portion of; its length as indicated at 8, and a drivingmember in theform of a pinion 9 is threaded-thereon forautomatic traversal into and out of engagement with a member such as a flywheel gear 11 of an engine to be started. The driving member 9 is normally retained in its idle position as illustrated in Fig. 1 by suitable anti-drift means such as a spring 12 bearing at one end against a stopnut 13 fixed to the shaft 2, and at the other end on a sliding collar 14 which rests against the end of the pinion 9. The stop nut 13 and/or collar 14 may be provided with recesses in order to housethe spring 12 when the pinion is in drivingfposition.

According to the present invention, means are provided for preventing'the pinion from bounding back toward the flywheel gear when. it is thrown out of engagement therewith as the engine starts. As illustrated more particularly in Figs. 2 and 3, this means comprises an arcuate lever 15 pivoted unsymmetrically to a. flange 16 of the pinion as indicated at 17-, and provided with a braking element 18 which is adapted to engage and bear on the shaft 2 whenthe lever 15 swings outwardly under the action of centrifugal force. In order to increase the braking effect of the element 18 and to produce a substantially balanced structure, according to the present invention a second arcuate lever 19 is pivoted to the flange 16 in a similar manner to the lever 15 as indicated at 21, and is provided with an arm 22 adapted to bear on a bevelled upper surface 23 of the braking element 18. It will thus be seen that centrifugal force acting on the long arms of the levers 15 and .19 will cause an inward pressure to be applied to the braking element 18 to restrict or pre= vent rotation of the pinion on the shaft 2. The normal or idle positions of the lever-s15 and 19 may be defined by suitable means such as a pin 24 mounted in the flange 16.

In order to lock the pinion 9 in its idle position under the action of the braking element 18, the shaft 2 is preferably provided with a shoulder 25 (Fig. 1) in position to be engaged by the braking element 18 when the pinion is in idle position. It will be understood that when the braking element 18 is forced down onto the shaft 2, back of the shoulder 25, longitudinal movement of the pinion 9 away from its idle position will be effectively prevented.

In the operation of this embodiment of the invention rotation of the power shaft 1 due to energization of the starting motor is transmitted to the hollow shaft 2 in the direction of the arrow whereby the pinion 9, due to its inertia is translated by the threads 8 into engagement with the engine gear 11. Further translation of the pinion 9 is prevented by the engagement of collar 14 with the stop nut 13 whereby the pinion is forced to rotate with the shaft 2 and crank the engine.

IVhen the engine starts, the acceleration of the flywheel gear 11 causes pinion9 to overrun the shaft 2 and thus be thrown back toward idle position. During this rapid rotation of the pinion 9, the braking element 18 reaches its idle position.

braking element 18 is forced down on the is forced against the shaft 2 by the centrifugal effect of the levers 15 and 19, whereby the excess energy of rotation of the pinion is largely dissipated by the time the pinion At this time, the

shaft 2 back of the shoulder 25 whereby the pinion is prevented from bounding back toward the engine gear.

In Figs. 1 and 5 there is illustrated a further embodiment of the invention in which the shaft 2 is provided with an arcuate depression 26 in position to be engaged by the braking element 18 when the pinion is in idle position, and the braking element 18 is formed to seat in said depression. This depression provides a locking connection between the braking element and the shaft which may be used in conjunction with the shoulder 25, or

. may be substitutedtherefor depending on the magnitude of the rebounding forces to be suppressed.

Although certain embodiments of the invention have been shown and described in detail, it will be understood that other embodiments are possible and that changes may be made in the construction and arrangements of'the parts without departing from the spirit of the invention as defined in the claims appended hereto.

What is claimed is:

'1. In anengine starter, a shaft, a driving member mounted for rotation thereon and therewith and for movement into and out of engagement with a member of an engine to be started, means responsive to rotation of the driving member for opposing relative rotation of the driving member and shaft, and means also responsive to rotation of the driving member for increasing the effect of said opposing means.

2. In an engine starter, a shaft, a driving member mounted for rotation thereon and therewith and for movement into and out of engagement with a member of an engine to be started, a centrifugal brake for retarding rotation of the driving member on the shaft and a centrifugal member for increas ing the force of application of said brake.

3. In an engine starter, a shaft, a driving member mounted for rotation thereon and therewith and for movement into and out of engagement with a member of an engine to be started, a centrifugal brake for retarding rotation of the driving member on the shaft, and a centrifugal member for increasing the force of application of said brake, said shaft being formed with a depression adapted to receive said brake when the driving member is in idle position.

4. In an engine starter, a shaft, a driving member mounted for rotation thereon and therewith and for movement into and out of engagement with a member of an engine to be started, a brake member mounted on said pinion and arranged to be moved by centrifugal force into engagement with said shaft, and a weighted lever also mounted on said pinion and operable by centrifugal force to urge said brake into engagement with said shaft.

5. In an engine starter, a shaft, a driving member mounted for rotation thereon and therewith and for movement into and out of engagement with a member of an engine to be started, an arcuate lever pivoted on said pinion near one end whereby rotation of the pinion causes said end to swing in and frictionally engage said shaft; and a second arcuate lever pivoted on said pinion symmetrically thereto and arranged to bear on said first lever when the pinion is rotated and thereby increase the frictional engagement of the first lever on said shaft.

In testimony whereof, I have hereunto signed my name.

ROBERT E. SLAYTON. 

